Roof and roofing sheets for use therein



l'ch 25, 1947. l `H, w. Asl-)MAN n '2,417,899

' ROOF AND RooFING SHEETS `FOR USE IHEREIN v Filed oct. 11, 1944 z'sneets-snee'c 1 March 25, 1947.

H. w. ASHMAN 2,417,899

ROOF AND ROOFING SHEETS .FOR USE THEREIN v Filed Oct. l1, 1944 2 Sheets-Sheet 2 Patented Mar. 25, 1947 v s PATENT OFFICE ROOF AND ROOFING SHEETS FOR USE THEREIN Herbert William Ashman, Hale, England vApplication October 11, 1944, Serial No. 558,143 In Great Britain November 2, 1943 (Cl. S-13.)

3 Claims. vl

Flat roofs are usually provided with a. continuous covering of asphalt or some bituminous material with or without layers of feltto render them water-tight. This covering is' wholly relied on to exclude rainwater, and if it has any cracks or weakness the roof may not be water-tight. Such coverings are usually black or dark in colour, are thus non-reflective to solar heat and accordingly provide poor insulation, and may be liable to soften or deteriorate under solar heat. In order` to protect them from the ldirect rays of the sun a top layer of light-coloured material is often applied to them, this layer also serving to provide a harder and more serviceable walking surface.

It is to be understood -that at roofs are rarely completely at. but usually have a slight fall, say in the order of 3 or 4 inches in 10 feet. The invention relates to any roofs that are technically called flat. v

My principal object is to provide sucha roof with an entirely diierent kind ci covering which will be waterproof, will provide a light-coloured surface that will reflect the suns rays and will be hard enough to carry the normal traiiic on a at roof.

Another object is to provide an improved roof covering composed of rigid sheets.

A further object is to provide novel corrugated sheets suitable for use in technically ilat roofs.

Yet another object isto provide a double covering for a rooi in which any water which may pass through the upper part will be led away to the edge of the roof by the lower part.

In my invention, I make the covering from two decks, each composed of sheets of asbestos-cement or equivalent rigid material. e. g. metal. the lower deck supporting the upper deck. 'Ihe sheets that compose the lower deck overlap one another at the sides and ends in theway usual in corrugated sheeting and if they were of ncrmal plane or corrugated construction they would not alone afford adequate resistance to the passage of water between them or through the holes made in them for i'lxing purposes. They are not,

however` of normal constructionv butl instead are corrugated to provide valleys or troughs which rest on the supporting framework or on a fiat surface covering the framework, inverted troughs which provide bearing surfaces for the upper deck, and flutes or rolls intermediate in height between the valleys or troughs and the inverted troughs. The fixing bolts or other devices for attaching the covering to the supports below pass through these flutes or rolls. The holes for these fixing bolts or the like are thus spaced above the valleys or troughs, which form the. lowermost part of the lower deck and in which any water that may pass through the upper deck collects. These valleys or troughs lead the water to the eaves or gutter. No reliance is placed on the upper deck for providing completely watertight joints, but naturally these are made as sound as possible so that the upper deck as a whole provides umbrella-like protection over the laps and xing holes in the lower deck, so that the risk of any water passing through the laps and xing holes is reduced to a minimum. y

The invention includes the sheets from which the lower deck is composed. In any such sheet there must be at least two valleys or troughs, at least one inverted trough and at least one flute or roll intermediate in height between the valleys or troughs and the inverted trough. The sheets composing the upper deck may be flat or of any convenient shape, and they may be internally reinforced if desired. They may abut or overlap or be joggled or rebated at the side joints, and particularly in the case of butt joints cover strips may be provided over the joints. TheI end joints preferably overlap, and it is best 'to arrange the joint in the upper deck slightly below the corresponding lap in the lower deck.

In order that the invention may be clearly understood and readily carried into eilect. some examples will 'now be described with reference to the accompanying drawings, in which:

Figure 1 isl a perspective view of la lowerdeck sheet;

Figure 2 is a perspective view of an upper deck sheet;

Figure 3 shows part of a lower deck composed of sheets as shown in Figure 1;

Figure 4 shows part of a roof covering formed by the lower deck shown in Figure 3 and an upper deckv composed of sheets as shown in Figure 2;

Figure 5 is a section on the line V-V in Figure 4; I

Figure 6 is an enlarged cross-section through part of the covering;

Figure 7 is-an enlarged longitudinal showing a modication; and

Figure 8 is an enlarged cross-section showing another modification.

One of the sheets of the lower deck is shown in Figure 1 and -is designated I. As an example ofltypical dimensions it may be '7 feet long and 3 feet 9 inches wide and it is corrugated length,-

section purlins or other members of the supporting framework as shown in Figures 3 to 5. Next to each valley or trough 4 is an inverted trough 6 and in the middle of each trough 6 is an upwardly projecting flute 1. The flat upper surfaces of each trough `6 on the two sides of the flute 1 form bearing surfaces for the sheets ofL the upper deck, and they may. for example, lie about 21/2 inches above the valleys 4. Between the two inverted troughs 6 are two more valleys or troughs 8 separated from one another by a flute 9, of approximately the same height vabove the valleys 4 and 8 as the side rolls 2. say about 11/2 inches. The central flute 9 and both the side rolls 2 and 3 are formed with holes for fixing bolts or` the like. These may be knuckle bolts I8 by which the sheets of the lower deck are secured to the purlins 5. f

The sheets composing the upper deck may be fiat, but it is preferred to corrugate them length wise. A typical sheet is shown at H in Figure 2 and it is essentially atbut has corrugations At one side it has a small roll 2 and at` on which the overlapping sheet Il' of rthe-upper deck rests lie in a single plane.

It may also be desirable to provide small transverse sinking or water grooves on the tops and sides of the inverted troughs just beyond the end joints to trap any moisture that may pene- I2 spacedfso that when the whole roof is assembled they lie over the flutes `1 `of the lower deck. The sheet il also has side rolls i3.

In assembling a complete roof the sheets l or the lower deck may iirstv be laid and bolted to the purlins, the sheets overlapping at the end joints as shown at I5. The sheets vII of the upper deck are then laid with overlapping joints as-shown at I5. As shown in Figure 5, it is best to arrange the joint i6 in the upper deck slightly below or down roof ofthe corresponding joint l5 in the lower deck. Thus at its end the righttrate through the joints and to lead it to the valleys or troughs. Such agroove is also illus- Y trated in Figure '1, where it is shown at 20. In

this particular arrangement the groove 20 is coincident with the part of the sheet I at which the end i9 is stepped up, but it will be understood that such a groove may be provided in a sheet devoid of any step at its end.

Figure 8 illustrates a covering in which the upper deck sheets are fiat. Two such sheets 2| are shown, the joint between them being rebated, as shown at 22. In the lower deck the flutes 1 are omitted so that the inverted troughs, one of which is shown at 23, present wholly flat bearing surfaces .for the upper deck. In this type of covering it is convenient to use bolts of the kind known as gutter bolts, seam bolts or stitching bolts for securing the upper deck to the lower deck through the inverted troughs, and one such bolt is shown at 24. In addition to washers 25, felt strips may also be interposed in the joints through which these bolts pafss.

I claim:

l. A roofing structure ofsuperposed rigid sheets carried by supports comprising a lower deck made up of a plurality of sheets overlapped hand upper deck sheet shown in` Figure 5^at X rests on a lower deck sheet Y, but for some of its bottom end it overlaps and restson` the top end of an upper deck sheet Z. Y

The upper deck is securedto the lower deck by bolts l1 which pass through the corrugations part at their `sides and ends and longitudinally corrugated to form inverted troughs of lesser and greater heights with valleys therebetween, the valleys of saidsheets resting upon the roof sup- .ports and fastening means passing through the crests of the inverted troughs of lesser height for aixing the lower deck sheets to said supports,

van upper deck of overlapping sheets resting upon the crests of the. inverted troughs of greater height of the lower deck sheets, and fastening I2 and the flutes 1 and are fitted with washers.

ts above and below. These bolts1l1 are not subjected to any pivoting action, so there is very little risk of leakage past them.

"The bolts l0 by which the lower deck is secured to the purlins are, it will be seen, covered by the upper deck. Such water as passes through the upper deck runs into the valleys which lead it to the eaves or gutter and does not tend to pass through the holes for the bolts i0.

It will be understood that the number of troughs, inverted troughs and utes and also their relative positions may be varied; For instance between any two inverted troughs there may be no ute or more than one flute, and again there may be a trough or valley-at one side of each sheet and an inverted trough at the other. L*

It is in the upper deck thicker than those in the lower deck. Such an arrangement is shown in Figure 7, and it will be seen underlapping sheet l in the lower deck is slightly stepped up so as to lift the overlapping sheet i of the same joint and thus make the surfaces that the end I9 of an means for attaching the upper to the lower deck 'at the crests of said inverted troughs of greater height.

k 2. A roof as definedin claim 1 wherein in each deck the sheets overlap at the end Joints and the end joints in the upper deck lie -slightly down ooi of thecorresponding joints in the lower eck.

3. A roof as dened in claim 1 wherein transverse grooves are formed on thev tops and sides of the inverted troughs of greater height below the end joints between the lower deck sheets.

HERBERT W'ILLIAM ASHMAN.

REFERENCES CITED The following references are of record in the file of `this patent:

` UNITED STATES PATENTS 

